Gauge/gravity duality, discovered in string theory in 1997, has became a powerful theoretical tool in the study of
quantum field theories at strong coupling. I will review recent attempts to use gauge/gravity duality to understand the physics of strongly interacting media, focusing on the quark gluon plasma and the cold atomic
gases. In particular, I will describe how the method has helped the discovery of new effects in relativistic
hydrodynamics that arise from triangle anomalies.
